Psalms 50:18

“When thou sawest a thief, then thou consentedst with him, etc.] Or “didst run with him” f677; joined and agreed with him in the commission of the same things; which was literally true of the Scribes and Pharisees: they devoured widows’ houses, and robbed them of their substance, under a pretence of long prayers; they consented to the deeds of Barabbas, a robber, when they preferred him to Jesus Christ; and they joined with the thieves on the cross in reviling him: and, in a spiritual sense, they stole away the word of the Lord, every man from his neighbour; took away the key of knowledge from the people, and put false glosses upon the sacred writings; and hast been a partaker with…”

“When thou sawest a thief - When you have seen or found one who was intending to commit theft, then (instead of rebuking or exposing him) you have been willing to act with him, and to divide the profits. The words “when thou sawest” would seem to imply readiness and willingness to engage with them, as “at first sight.” Whenever there was an opportunity to share in the results of theft, they were ready to engage in it. The main “point” in this is, that they were willing to do so even when observing the outward duties of religion, and when professing to be the true worshippers of God. A similar sentiment occurs in Romans 2:21. See the notes at that passage. Then thou consentedst with him -…”

“consentedst: Pro 1:10-19; Isa 5:23; Mic 7:3; Rom 1:32; Eph 5:11-13 hast been partaker: Heb. thy portion was, Lev 20:10; Job 31:9-11; Pro 2:16-19, Pro 7:19-23; Jer 5:8, Jer 5:9; Heb 13:4 partaker: Mat 23:30; Ti1 5:22 Psalms 50:19”