ק֤וֹל ׀ רִנָּ֬ה וִֽישׁוּעָ֗ה בְּאָהֳלֵ֥י צַדִּיקִ֑ים יְמִ֥ין יְ֝הוָה עֹ֣שָׂה חָֽיִל׃
Le son des chants de joie et de salut [retentit] dans les tentes des justes: la droite de l’Éternel procure la victoire.
Rabbeinu Bahya
According to Mechilta (Pisscha 16) the month of spring is the one in which מוציא אסירים בכושרות, “G’d releases prisoners when they are in chains.” (Psalms 68,7) The word בכושרות may be understood as “in a suitable (כשר) month.” Rabbi Yochanan understands the word as a combination of בכי ושירות, “weeping and songs of jubilation.” On the one hand, there was not a single Egyptian house in which there was not at least one dead, causing weeping, whereas on the other hand, the Israelites broke out in joyful song as described in Psalms 118,15 קול רנה וישועה באהלי צדיקים, “the tents of the righteous resound with the joyous shouts of deliverance.”