וַיִּשָּׂ֨א דָוִ֜ד וְהָעָ֧ם אֲשֶׁר־אִתּ֛וֹ אֶת־קוֹלָ֖ם וַיִּבְכּ֑וּ עַ֣ד אֲשֶׁ֧ר אֵין־בָּהֶ֛ם כֹּ֖חַ לִבְכּֽוֹת׃
Then David and the people that were with him lifted up their voice and wept, until they had no more power to weep.
Read midrashic interpretation of I Samuel 30:4: and classical rabbinic exegesis.