C. F. Keil and Franz Delitzsch on Jeremiah 15:17

Jer 15:17

To this calling he has devoted his whole life: has not sat in the assembly of the laughers, nor made merry with them; but sat alone, i.e., avoided all cheerful company. Because of Thy hand, i.e., because Thy hand had laid hold on me. The hand of Jahveh is the divine power which took possession of the prophets, transported their spirit to the ecstatic domain of inner vision, and impelled to prophesy; cf. Jer 20:7; Isa 8:11; Eze 1:3, etc. Alone I sat, because Thou hast filled me with indignation. זעם is the wrath of God against the moral corruptness and infatuation of Judah, with which the Spirit of God has filled Jeremiah in order that he may publish it abroad, cf. Jer 6:11. The sadness of what he had to publish filled his heart with the deepest grief, and constrained him to keep far from all cheery good fellowship.