John Gill Commentary Mark 16:14

"And afterward he was manifested unto the eleven themselves as they sat at meat; and he upbraided them with their unbelief and hardness of heart, because they believed not them that had seen him after he was risen." — Mark 16:14 (ASV)

Afterward he appeared unto the eleven
Apostles; for this was now the number of them, Judas being gone from them, and dead; and they were so called, though Thomas was not now with them, because their whole company consisted of this number: this appearance of Christ to them was on the same first day of the week, at evening, (John 20:19) , though it must be very late at night; for it was after the two above disciples were returned from Emmaus, where Christ and they had supped together; see (Luke 24:29Luke 24:30Luke 24:33Luke 24:36) ;

as they sat at meat ;
or "sat together"; being assembled together, and the doors shut fast for fear of the Jews, (John 20:19) , and so the Arabic renders it, "while they were gathered together"; and the Persic version, "who being gathered together were sitting": nor does the word necessarily signify sitting at meat; nor is it very likely that they should be eating so late at night; though it is probable they had been eating, as seems from (Luke 24:41–43) ;

and upbraided them with their unbelief, and hardness of heart :
not but that their hearts were very contrite for their sinful carriage to Christ; and very much humbled they were under the present dispensation: their hearts were much affected, and they were filled with sorrow and trouble for the loss of Christ; but in this point their unbelief increased by their fears, and so much prevailed, that all that were said by one, and another, made no impression on them: and a great aggravation of their incredulity, and a reason of Christ's upbraiding them in this manner were,

because they believed not them which had seen him after he was
risen ;
as Mary Magdalene, and the other women, and Cleophas, and the other disciple that was with him, who were eyewitnesses that he was risen from the dead; and such as might have been depended on.