On Saturday, the high priests and Pharisees gathered together before Pilate and asked him to have Jesus’ tomb sealed until the third day; because, as those enemies of God said, “We suspect that His disciples will come and steal His buried body by night, and then proclaim to the people that His resurrection is true, as that deceiver Himself foretold while He was yet alive; and then the last deception shall be worse than the first.”
After they had said these things to Pilate and received his permission, they went and sealed the tomb, and assigned a watch for security, that is, guards from among the soldiers under the supervision of the high priests
62 The next day, which was a Sabbath, the chief priests and the Pharisees met with Pontius Pilate63 and said, “Sir, remember that while that liar was still alive he said, “I will be raised to life three days later.’64 Give orders, then, for his tomb to be carefully guarded until the third day, so that his disciples will not be able to go and steal the body, and then tell the people that he was raised from death. This last lie would be even worse than the first one.”65“Take a guard,” Pilate told them; “go and make the tomb as secure as you can.”66 So they left and made the tomb secure by putting a seal on the stone and leaving the guard on watch. (Matt. 27:62-66).
While commemorating the entombment of the holy Body of our Lord today, we also celebrate His dread descent with His soul, whereby He destroyed the gates and bars of Hades, and made His light to shine where only darkness had reigned (Job 3 8 : 17; Esaias 49:9; 1 Peter 3:18-20); death was put to death.
Hades was stripped of all its captives, our first parents (Adam and Eve and their descendant) and all the righteous who died from the beginning of time ran to Him Whom they had awaited, and the holy angelic orders glorified God for the restoration of our fallen race.

Apolytikion of Holy Saturday in the Second Tone
Lowering Your pure body from the Cross, Joseph wrapped it in clean muslin with fragrant spices and laid it in a new tomb.
When You descended to death, O Immortal Life, then, the light of Your ddivinity destroyed Hades.
When You raised the dead from the depths of darkness, all the heavenly powers cried out, “Glory to You our Christ, the Giver of Life.” Standing by the tomb the angel said to the Myrrh-bearing women: “Myrrh is for the dead; but Christ has shown Himself stranger to death.”
Kontakion of Holy Saturday in the Second Tone
He Who enclosed the deeps is now seen dead; and the immortal One is laid in a tomb enclosed in a shroud with myrrh. Women, too, come to anoint Him, weeping bitterly and lamenting: “This Sabbath is blessed above all others, for Christ, having fallen asleep, will rise on the third day.”