Is it counted for the latecomer to combine Maghrib and Isha if he caught them before the tasleem in both prayers?

The latecomer to the Maghrib prayer due to rain may combine the prayers if he intends to do so. He should complete the Maghrib prayer, then join the congregation for the Isha prayer and complete what he missed of it, based on the Prophet's (peace be upon him) saying: "So whatever you catch up with, pray, and whatever you miss, complete." He will attain the virtue of congregational prayer by joining it before the Imam's salutation.