Either from discontent of mind, as Ahab did, 1 Kings 21:4; or from sloth and sensuality, as David seems to have done, 2 Samuel 11:2.
Related Commentaries of 2 Samuel 4:5
2 Samuel 4:5
5 And the sons of Rimmon the Beerothite, Rechab and Baanah, went, and came about the heat of the day to the house of Ishbosheth, who lay on a bed at noon.