(19) Then God opened (Hagar's) eyes and she saw a well of water. She went and filled the skin with water, and let the boy drink.
וַיִּקְרָ֨א אֵלָ֜יו מַלְאַ֤ךְ יְהוָה֙ מִן־הַשָּׁמַ֔יִם וַיֹּ֖אמֶר אַבְרָהָ֣ם ׀ אַבְרָהָ֑ם וַיֹּ֖אמֶר הִנֵּֽנִי׃ וַיֹּ֗אמֶר אַל־תִּשְׁלַ֤ח יָֽדְךָ֙ אֶל־הַנַּ֔עַר וְאַל־תַּ֥עַשׂ ל֖וֹ מְא֑וּמָּה כִּ֣י ׀ עַתָּ֣ה יָדַ֗עְתִּי כִּֽי־יְרֵ֤א אֱלֹהִים֙ אַ֔תָּה וְלֹ֥א חָשַׂ֛כְתָּ אֶת־בִּנְךָ֥ אֶת־יְחִידְךָ֖ מִמֶּֽנִּי׃ וַיִּשָּׂ֨א אַבְרָהָ֜ם אֶת־עֵינָ֗יו וַיַּרְא֙ וְהִנֵּה־אַ֔יִל אַחַ֕ר נֶאֱחַ֥ז בַּסְּבַ֖ךְ בְּקַרְנָ֑יו וַיֵּ֤לֶךְ אַבְרָהָם֙ וַיִּקַּ֣ח אֶת־הָאַ֔יִל וַיַּעֲלֵ֥הוּ לְעֹלָ֖ה תַּ֥חַת בְּנֽוֹ׃
Then an angel of the LORD called to him from heaven: “Abraham! Abraham!” And he answered, “Here I am.”And he said, “Do not raise your hand against the boy, or do anything to him. For now I know that you fear God, since you have not withheld your son, your favored one, from Me.” When Abraham looked up, his eye fell upon a ram, caught in the thicket by its horns. So Abraham went and took the ram and offered it up as a burnt offering in place of his son.
Opening Our Eyes, Rabbi Rami Shapiro
The miracle is spiritual rather than physical of supernatural. The well had always been there, but Hagar, paralyzed by fear, despair, and her own sense of powerlessness, was blinded to the possibility of salvation. In calling out to God, she finds the strength to discover what she needs to do. Only then does Hagar see the well.
Hagar's example can serve as a comfort and an inspiration when the pain and difficulty of our own lives seem too overwhelming, when taking the next step seems impossible. We are reminded that there are always unseen possibilities. As we call out in prayer during the Yamim Nora'im, we, too, can reorient our vision, see new possibilities in our lives and adjust our attitudes and actions. (from Rosh Hashanah Readings, 103)