No, it doesn't mention keeping the sabbath.
Would you say that the Sabbath Day was strongly implied?
Here are the verses in question again, the comparison is between Rev. 14:7 and Exo. 20:11.
This is the final message of mercy to earth’s inhabitants, 1) it calls on man to worship the creator “7 Saying with a loud voice, Fear God, and give glory to him; for the hour of his judgment is come: and
worship him that made heaven, and earth, and the sea, and the fountains of waters.”
[Exo 20:8-11 KJV] 8
Remember the sabbath day, to keep it holy. 9 Six days shalt thou labour, and do all thy work: 10 But the seventh day [is] the sabbath of the LORD thy God: [in it] thou shalt not do any work, thou, nor thy son, nor thy daughter, thy manservant, nor thy maidservant, nor thy cattle, nor thy stranger that [is] within thy gates: 11
For [in] six days the LORD made heaven and earth, the sea, and all that in them [is], and rested the seventh day: wherefore the LORD blessed the sabbath day, and hallowed it.
This is the account provided concerning the actions of Jesus, the creator on the first Sabbath Day in the world’ history, please see John’s accounts of the creation below.
[Gen 2:1-3 KJV] 1 Thus the heavens and the earth were finished, and all the host of them. 2 And
on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made. 3 And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made.
[Jhn 1:1-5 KJV] 1 In the beginning was the Word, and the Word was with God, and the Word was God. 2 The same was in the beginning with God. 3 All things were made by him; and without him was not any thing made that was made. 4 In him was life; and the life was the light of men. 5 And the light shineth in darkness; and the darkness comprehended it not.
[Jhn 1:1-5, 10-14 KJV] 1 In the beginning was the Word, and the Word was with God, and the Word was God. 2 The same was in the beginning with God. 3
All things were made by him; and without him was not any thing made that was made. 4 In him was life; and the life was the light of men. 5 And the light shineth in darkness; and the darkness comprehended it not. ... 10 He was in the world, and the world was made by him, and the world knew him not. 11 He came unto his own, and his own received him not. 12 But as many as received him, to them gave he power to become the sons of God, [even] to them that believe on his name: 13 Which were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God.
14 And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.