Rashi, on Ps 17:30

“For by thee I shall be delivered from temptation; and through my God I shall go over a wall.”

“For by You By Your assurance. and by my God I scale a wall When he came to wage war against Jebus, and he said (in I Chron. 11:6): “Whoever smites the Jebusites, etc. shall be a leader and a prince.” Joab brought a green juniper tree, bent it over, suspended himself on it, and scaled the wall. Said David (in Ps. 141:5): “May a righteous man smite me with loving-kindness,” and the Holy one, blessed be He, lowered the wall, and he scaled it (Mid. Ps. 18:24).”

Imported from an open dataset — not yet checked against the printed edition.