Introduction to Psalm 138/1

Psalm 138 is surely one of the most beautiful of the poems of the psalter, and it is relatively unusual in that, rather than condensing in references to many events and ideas, it lingers very much on one theme, namely God's omniscience and omnipotence.

St Benedict's psalter splits Psalm 138 into two sections, both said at Thursday Vespers.

The use of Psalm 138 (137) in the Benedictine Office

It is not actually that long a psalm, consisting of 23 verses in total, and so the divisio results in Thursday being one of the shorter days of the week at Vespers.  So why does the saint split the psalm in two?

The answer seems to be, in part at least, that this is the prayer of the Garden, and as such it takes us deep into the contemplation of God's love of us, the intimacy of the Trinity, and the fate Our Lord was contemplating.

Its use on the fifth day of the week may also reflect its allusion to the things created on that day in the Genesis account, viz things that fly and those that inhabit the sea (verse 9).

The text of the psalm

Psalm 138/1 – Domine probasti me

Vulgate (Numbering follows psalmody)	Douay-Rheims (numbering follows DR)
In finem, psalmus David.	Unto the end, a psalm of David.
Dómine, probásti me, et cognovísti me: * tu cognovísti sessiónem meam, et resurrectiónem meam.	1 Lord, you have proved me, and known me: 2 You have known my sitting down, and my rising up.
2  Intellexísti cogitatiónes meas de longe: * sémitam meam, et funículum meum investigásti.	You have understood my thoughts afar off: my path and my line you have searched out.
3  Et omnes vias meas prævidísti: * quia non est sermo in lingua mea.	4 And you have foreseen all my ways: for there is no speech in my tongue.
4  Ecce, Dómine, tu cognovísti ómnia novíssima, et antíqua: * tu formásti me, et posuísti super me manum tuam.	5 Behold, O Lord, you have known all things, the last and those of old: you have formed me, and have laid your hand upon me.
5  Mirábilis facta est sciéntia tua ex me: * confortáta est, et non pótero ad eam.	6 Your knowledge has become wonderful to me: it is high, and I cannot reach to it
6  Quo ibo a spíritu tuo? * et quo a fácie tua fúgiam?	7 Whither shall I go from your spirit? Or whither shall I flee from your face?
7  Si ascéndero in cælum, tu illic es: * si descéndero in inférnum, ades.	8 If I ascend into heaven, you are there: if I descend into hell, you are present.
8  Si súmpsero pennas meas dilúculo, * et habitávero in extrémis maris.	9 If I take my wings early in the morning, and dwell in the uttermost parts of the sea:
9  Etenim illuc manus tua dedúcet me: * et tenébit me déxtera tua.	10 Even there also shall your hand lead me: and your right hand shall hold me.

Literal meaning of the psalm 

St Benedict's split of the psalm should further encourage us to take this psalm slowly, and ponder the depths of its meaning.

At the literal level, there is a gentle progression of ideas in this half of the psalm.  The opening verses point to God's omniscience: he knows everything about us (verses 1-4); we on the other hand, can never really comprehend the mystery that is God (verse 5).  The second half of this part of the psalm points to God's presence everywhere and in everything (verses 7-9): on the one hand the sinner can never hope to evade him; but on the positive side, he is always there to help an protect us, enabling us to withstand even the most dire disasters in our lives (verse 10).

Christological interpretation

The Fathers, though, also gave this psalm a Christological interpretation, putting those questions about where he should go - to heaven, hades or the foremost ends of the earth - rhetorically on Christ's lips as he pondered the coming events of the Sacred Triduum.  Cassiodorus summarises it thus:

So this entire psalm — and this is also the view of the most learned father Hilary — is to be recited by the mouth of the Lord Christ. His lowliness must not however trouble or disturb anyone; to avoid this, each must have recourse to the canon of Catholic teaching, to remember that there are two natures united and perfected in the Lord Christ. The first is that by which He is God, coeternal with the Father; the second that by which He was born of the virgin Mary, and as one and the same Person deigned in time to become Man for our salvation. So the fact that He speaks in humble tones must not be a reflection on His divinity, but is to be understood in accordance with the mystery of the holy incarnation. Once we have considered this reasoning, we can acknowledge the divine mysteries without stumbling.

In this light, in this first section of the psalm, according to Cassiodorus, "He recounts to the Father His death and resurrection, observing that all His thoughts are well known to the Father."

The answer to the question the psalm asks, of course, is that even when he descends into hades, his divine nature guides him, so that the Resurrection can occur.

Liturgical and scriptural uses of the psalm

NT references	Heb 4:13 (1)
RB cursus	Thurs Vespers+AN 2367 (1)
Monastic feasts etc	2 Vespers of Apostles (+John the Baptist, St Benedict, St Joseph)
Roman pre 1911	Friday Vespers
Responsories	7629 Job not 1962 (8);
Roman post 1911	1911-62: Friday Vespers  . 1970:
Mass propers (EF)	Easter day (Resurrexi) IN (1) SS Peter and Paul (Nunc scio), IN (1) Andrew (Mihi autem), IN (1), OF V (1) Conversion of St Paul IN (Scio cui)

You can find the first set of verse by verse notes on this psalm here.