Well that is not true your question was how did the Israelites in the exodus know to worship on the Sabbath? I already answered this by showing from the scriptures we "worship God" by doing what Gods' Word says as shown in scriptures such as Matthew 15:2-9 that show that if we do not do what God asks us to do we are not worshiping God.
Ezekiel 46:1-3 and
Isaiah 66:22-23 from he very spoken Words of God that we are to worship God on the Sabbath. What we do know from the scriptures is that Gods' people kept the Sabbath and God tells us that by keeping the Sabbath we worship him. That is all we need to know isn't it?
Worshipping God was not done by Israel, is what Matthew 15 shows, was never done but was broken.
Israel continues to seek God by the same laws.
Seeking the Father is by the Son ( believing in His death during the sabbath and rising at the end of it showing how Christ entered His rest and rose to glory) by faith and not by the law that not only is not faith, but the letter kills.
The prince entered not in earthly sabbaths, but in His glorious one. We also go up to heavenly places with him in that heavenly sabbath and seventh day...
Ezekiel 46:2 And the prince shall enter by the way of the porch of that gate without, and shall stand by the post of the gate, and the priests shall prepare his burnt offering and his peace offerings, and he shall worship at the threshold of the gate: then he shall go forth; but the gate shall not be shut until the evening.
3 Likewise the people of the land shall worship at the door of this gate before the Lord in the sabbaths and in the new moons.
Ephesians 2:6 And hath raised us up together, and made us sit together in heavenly places in Christ Jesus:
All on this earth ( earthly sabbaths is temporary) does not exist, only up in heaven we exist with God..
2 Corinthians 4:18 While we look not at the things which are seen, but at the things which are not seen: for the things which are seen are temporal; but the things which are not seen are eternal.