Albert Barnes Commentary 1 Kings 3:1

"And Solomon made affinity with Pharaoh king of Egypt, and took Pharaoh`s daughter, and brought her into the city of David, until he had made an end of building his own house, and the house of Jehovah, and the wall of Jerusalem round about." — 1 Kings 3:1 (ASV)

It is uncertain which Pharaoh is meant. It must have been a predecessor of Shishak (or Sheshonk), who invaded Judea more than forty years later (1 Kings 14:25). The evidence suggests it was not Psusennes II, the last king of Manetho’s 21st dynasty, but his predecessor, Psinaces. This Tanite dynasty had become very weak, especially toward its end. From this, we can understand why it would have gladly allied itself with the powerful house of David.

The Jews were not forbidden to marry foreign wives if they became proselytes. Since Solomon is not blamed for this marriage either here or in 1 Kings 11:1, and since the idol temples he allowed to be built (1 Kings 11:5–7) were in no case dedicated to Egyptian deities, we can presume that his Egyptian wife adopted her husband’s religion.

The city of David—This refers to the city situated on the eastern hill, or the true Zion, where the temple was later built, opposite the city of the Jebusites (1 Kings 9:24; compare to 2 Chronicles 8:11).