The Talmud expounds "לעת מצא" as referring to the moment of finding a wife, a burial plot, or — according to Rava — the time of death itself. It teaches that one should pray at these pivotal moments of life, establishing 'עת' as a window of divine grace.
״עַל זֹאת יִתְפַּלֵּל כָּל חָסִיד אֵלֶיךָ לְעֵת מְצֹא״, אָמַר רַבִּי חֲנִינָא: ״לְעֵת מְצֹא״ זוֹ אִשָּׁה, שֶׁנֶּאֱמַר: ״מָצָא אִשָּׁה מָצָא טוֹב״. רַב נַחְמָן בַּר יִצְחָק אָמַר — ״לְעֵת מְצֹא״ זוֹ מִיתָה, שֶׁנֶּאֱמַר: ״לַמָּוֶת תּוֹצָאוֹת״. רַבִּי יוֹחָנָן אָמַר: ״לְעֵת מְצֹא״ — זוֹ קְבוּרָה. אָמַר רַבִּי חֲנִינָא, מַאי קְרָא ״הַשְּׂמֵחִים אֱלֵי גִיל יָשִׂישׂוּ כִּי יִמְצְאוּ קָבֶר״. אָמַר רַבָּה בַּר רַב שֵׁילָא, הַיְינוּ דְּאָמְרִי אִינָשֵׁי: לִיבְעֵי אִינָשׁ רַחֲמֵי אֲפִילּוּ עַד זִיבּוּלָא בָּתְרָיְיתָא שְׁלָמָא.
Having mentioned the verse, “For whoso finds Me finds life,” the Gemara seeks to clarify its meaning. It is said, “For this, let every pious man pray to You in the time of finding, that the overflowing waters may not reach him” (Psalms 32:6). With regard to the phrase, the time of finding, Rabbi Ḥanina said: The time of finding refers to the time one must find a wife, that one should pray to find a suitable woman to marry. As it is said: “He who finds [matza] a wife finds [matza] good and obtains favor from the Lord” (Proverbs 18:22). Rav Naḥman bar Yitzḥak said: The time of finding refers to death. One should pray that when death comes, he will leave the world peacefully, as it is stated: “Issues [totzaot] of death” (Psalms 68:21). Rav Naḥman bar Yitzḥak’s statement is based on the etymological similarity between totzaot and matza, finding. Rabbi Yoḥanan said: The time of finding refers to a respectful burial, for which one should pray. Supporting Rabbi Yoḥanan’s interpretation, Rabbi Ḥanina said: What is the verse that teaches that the time of finding refers to burial? “Who rejoice in exultation and are glad when they can find a grave” (Job 3:22), as there are situations in which one is relieved when his body finds a grave in which to rest. Rabba bar Rav Sheila said, that is the meaning of the folk saying: A person should even pray for mercy until the final shovelful of dirt is thrown upon his grave.