"And it came to pass in the morning watch" (Exodus 14:24). You find that the prayers of the righteous are heard in the morning. The morning of Abraham, as it is written, "And Abraham rose early in the morning" (Genesis 22:3). The morning of Samuel, as it is said, "And Samuel rose early to meet Saul in the morning" (1 Samuel 15:12). The morning of the prophets who are destined to arise, as it is said, "O LORD, in the morning You will hear my voice" (Psalms 5:4). The morning of the World to Come, as it is said, "They are new every morning" (Lamentations 3:23).
The Prayers of the Righteous Are Heard in the Morning
Yalkut Shimoni on Torah 235:2
וַיְהִי בְּאַשְׁמֹרֶת הַבֹּקֶר. אַתָּה מוֹצֵא שֶׁתְּפִלָּתָן שֶׁל צַדִּיקִים נִשְׁמָעִין בַּבֹּקֶר, בָּקְרוֹ שֶׁל אַבְרָהָם, "וַיַּשְׁכֵּם אַבְרָהָם בַּבֹּקֶר", בָּקְרוֹ שֶׁל שְׁמוּאֵל, (שמואל א טו, יב) "וַיַּשְׁכֵּם שְׁמוּאֵל לִקְרַאת שָׁאוּל בַּבֹּקֶר", בָּקְרָן שֶׁל נְבִיאִים שֶׁעֲתִידִין לַעֲמֹד, שֶׁנֶּאֱמַר (תהלים ה, ד) "ה' בֹּקֶר תִּשְׁמַע קוֹלִי", בָּקְרוֹ שֶׁל עוֹלָם הַבָּא, שֶׁנֶּאֱמַר (איכה ג, כג) "חֲדָשִׁים לַבְּקָרִים".