1 Samuel 7:6

They gathered together to Mizpeh, and drew water, and poured it out— The reason why they drew water and poured it out, says Houbigant, is expressed in the next words; for they fasted that day. So David poured on the ground the water which some of his soldiers brought him at the hazard of their lives through the midst of the enemy; for this was a part of the ceremonial of fasting. The Chaldee, however, renders the words, they poured out their souls in penitence, like waters before the Lord; and Grotius expressly asserts, that the waters poured out signify tears. There are a variety of other conjectures on this passage. L'Empereur refers the words to those in Isaiah 12:3 compared with John 7:37; supposing that the water was poured out in token of joy, after they had fasted and confessed their sins, (for he translates the words after they had fasted on that day,) as they always did on the feast of tabernacles: libations of water were anciently very common. We learn from Porphyry, that at the beginning libations were usually made with water; honey was afterwards employed, and then wine. See Porphyry de Abstinent. lib. ii. p. 156. We have proofs of this in Homer too, Od. lib. xiv. ver. 350. and Virg. AEn. iv. ver. 512. Though the law ordains nothing respecting libations of water, it nowhere forbids them, especially upon extraordinary occasions. See Calmet on the place.