Or HaChaim on Genesis 12:7/אור החיים על בראשית י״ב:ז׳

1 וירא ה׳ אל אברם. G'd appeared to Abram. The Torah wishes to compliment Abraham on his great love for his Creator. G'd appeared to Abraham and promised him not only children but that his descendants would inherit the land he was on. Abraham considered the mere fact that G'd appeared to him as sufficient reason to build an altar for G'd. The feeling that G'd had deemed him worthy to appear to him was so overpowering that Abraham considered the promise of children and of the land as secondary. This is why the Torah stresses that he built the altar "to the G'd who appeared to him." This is what David said in Psalms 16,11: "In Your presence is perfect joy." Perhaps we find an echo of these sentiments when Ben Azzai declined to marry, saying that he was so in love with Torah that he could not do justice to the demands made upon him by marriage ( Yevamot 63).