וַיְהִ֣י אַבְרָ֔ם בֶּן־תִּשְׁעִ֥ים שָׁנָ֖ה וְתֵ֣שַׁע שָׁנִ֑ים וַיֵּרָ֨א יְהוָ֜ה אֶל־אַבְרָ֗ם וַיֹּ֤אמֶר אֵלָיו֙ אֲנִי־אֵ֣ל שַׁדַּ֔י הִתְהַלֵּ֥ךְ לְפָנַ֖י וֶהְיֵ֥ה תָמִֽים׃
И когда Авраму было девяносто девять лет, Господь явился Авраму и сказал ему: 'Я Бог Всемогущий; ходи предо Мною и будь от всего сердца.
The Midrash of Philo
Why when he was ninety and nine years old does the sacred writer say, "The Lord God appeared to him and said, I am the Lord thy God?" (Genesis 17:1).
On the Change of Names
[1] “Abraham became ninety-nine years old and the Lord was seen by Abraham and said to him, ‘I am thy God’ ” (Gen. 17:1). Nine plus ninety is next neighbour to a hundred, the number irradiated by the self-taught nature Isaac who is joy, the best of the good emotions. For Isaac is born to Abraham when a hundred years old.
The Midrash of Philo
What is the meaning of, "Do thou please me, and keep thyself from stain, and I will make my treaty between me and thee, and I will multiply thee exceedingly?" (Genesis 17:1).