Radak, on Ps 4:8

“By the fruit of their corn, their wine and oil, they are multiplied.”

“Thou hast put gladness in my heart: – Behold, they requite me evil for good, but, as for me, there was gladness in my heart at their prosperity – that is, From the time when their corn and wine multiplied: – and they are rejoicing at my evil. And the meaning of Thou hast put is in the sense of what they have said (Babli, Yoma 38 b, and in other places), “He who comes to be purified is helped.” And it is a good way for a man to rejoice in the prosperity of his fellows. And him who walks in a good way God helps and directs: and this is the force of Thou hast put.”

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