(And they will be judged) meaning, all of creation.
(with truth.) Then He says:
(And it will be said, "All the praises and thanks be to Allah, the Lord of all that exits.") meaning, all of creation, whether animate or inanimate, will speak words of praise to Allah, the Lord of all that exists, for His wisdom and justice. These words are not attributed to any specific speaker, which indicates that the whole of creation will testify to His praise. Qatadah said, "Allah began His creation with praise, as He said,
(All praises and thanks be to Allah, Who created the heavens and the earth) (6:1). and He ended it with praise, as He says:
(And they will be judged with truth. And it will be said, "All the praises and thanks be to Allah, the Lord of all that exists.")."