Psalms 136:1

Brenton_Greek⁽ⁱ⁾ ¹ Ἀλληλούΐα.
Ἐξομολογεῖσθε τῷ Κυρίῳ, ὅτι ἀγαθὸς, ὅτι εἰς τὸν αἰῶνα τὸ ἔλεος αὐτοῦ.

Online Parallel Study Bible

Psalms 136:1 An exhortation to give thanks to God for particular mercies.

(Title.)This Psalm is little else than a repetition of the preceding, with the addition of the burden, "for his mercy endureth for ever," at the end of each verse; and it was doubtless composed on the same occasion. It seems evidently to have been a responsive song; the first part of the verse being probably sung by the Levites, and the burden by the people.
Give thanks.
Psalms 105:1; Psalms 106:1; Psalms 107:1; Psalms 118:1; Psalms 119:68; 2 Chronicles 7:3; 2 Chronicles 7:6; Ezra 3:11; Jeremiah 33:11
for his mercy.
Psalms 103:17; 1 Chronicles 16:34; 1 Chronicles 16:41; 2 Chronicles 20:21; Luke 1:50; Jude 1:21