They limited either,
1. God's power, as above, Psalms 78:19,20. Or,
2. God's will, directing and prescribing to him what to do, and when, and in what manner, and murmuring at him if he did not always grant their particular and various desires.
Related Commentaries of Psalms 78:41
Psalms 78:41
41 Yea, they turned back and tempted God, and limited the Holy One of Israel.