When did the saints who were raised with Christ come out of their graves?
The saints who were raised with Christ came out of their graves after He had been resurrected Himself, not while He was on the cross. Christ had to be the first to be resurrected, and then these Jewish believers were resurrected from cemeteries around Jerusalem and appeared in the city.
Les explains that the saints did not come out of the grave while Christ was on the cross; they came out after He had been resurrected Himself, because Christ had to be the first. This fulfilled the sheaf analogy of the first fruits, requiring other examples of resurrection. Some Jewish believers were resurrected from cemeteries around Jerusalem, came into the city, and appeared probably to their friends and relatives. Since Christ in His resurrected body ascended into heaven, these saints did as well. They were not like Lazarus, who came back to die again; these were resurrected believers given immortality and no doubt taken up into heaven. That makes them the sheaf of the first fruits, the beginning of the first resurrection.