Genesis 26:24-25

And the LORD appeared unto him the same night, and said, I am the God of Abraham thy father: fear not, for I am with thee, and will bless thee, and multiply thy seed for my servant Abraham's sake.

The Lord appeared unto him the same night. 'Man's extremity is God's opportunity;' and so Isaac found it to be; because no sooner had he arrived at Beer-sheba, disappointed, wearied, and troubled by the unceasing molestation of his Philistine neighbours, who would not permit him to settle in any one place within their territories (Genesis 21:32, last clause), than during that same night, God, by a seasonable revelation, was pleased to delight his drooping spirit with the comforts of grace, so that, being "strong in the Lord," he was raised above the fear of man. He was then ardent in devotional feeling, stedfast in maintaining habitual communion with God, and was not wanting in acknowledgments for present tokens of the divine favour by 'building an altar there, and calling upon the name of the Lord. Abraham had reared an altar in Beer-sheba long before (Genesis 21:33); Isaac reared another (Genesis 26:25), which, as has been remarked by Jewish writers, is the only one he is recorded to have raised.