Wilt thou be angry with us for ever? - Thine anger is so long continued that it seems as if it would never cease.
Wilt thou draw out thine anger - Wilt thou protract or prolong it? The idea is that of a determined purpose, in retaining his anger, as if his wrath would cease of necessity unless there were such a direct exercise of will.
To all generations - literally, “from generation to generation.” That is, - so that not merely the generation which has sinned, and which has brought down these tokens of displeasure, shall suffer, but the next, and the next, and the next, forever. The plea is that the judgment might terminate, and not reach coming generations.