It pleased David; as for other reasons, so especially because this opened the door to the kingdom which God had promised him. The days, i.e. the time allowed by Saul to David for the execution of this exploit.
Related Commentaries of 1 Samuel 18:26
1 Samuel 18:26
26 And when his servants told David these words, it pleased David well to be the king's son in law: and the days were not expired.e