What is the biblical basis for only keeping the weekly Sabbath while disregarding all the other feasts/holy convocations (Lev 23, Num 28, 29)?

Leviticus 23 introduces several appointed festivals/holy convocations. The chapter starts with: > The Lord said to Moses, > > 2 “Speak to the Israelites and say to them: ‘These are my **appointed festivals**, the appointed festivals of the Lord, which you are to proclaim as **sacred assemblies**. - Lev 23:1-2 (NIV) Then the festivals / holy convocations are enumerated: 1. **The weekly Sabbath** (Lev 23:3) 2. The Passover and the Festival of Unleavened Bread (Lev 23:4-8) 3. Offering the Firstfruits (Lev 23:9-14) 4. The Festival of Weeks (Lev 23:15-22) 5. The Festival of Trumpets (Lev 23:23-25) 6. The Day of Atonement (Lev 23:26-32) 7. The Festival of Tabernacles (Lev 23:33-44) Similarly, in Numbers 28 and 29 we find a similar list: 1. Daily Offerings (Num 28:1-8) 2. **Sabbath Offerings** (Num 28:9-10) 3. Monthly Offerings (a.k.a. New Moons) (Num 28:11-15) 4. The Passover (Num 28:16-25) 5. The Festival of Weeks (Num 28:26-31) 6. The Festival of Trumpets (Num 29:1-6) 7. The Day of Atonement (Num 29:7-11) 8. The Festival of Tabernacles (Num 29:12-40) It's not rare to come across Christians who claim that the weekly sabbath (Lev 23:3, Num 28:9-10) is still in effect, while all the other festivals and holy convocations are not (e.g. (https://sdarm.org/publications/periodicals/sbl/en/2009/1/11) , (https://naturesanswer.com/topic/colossians-2%3A16-sabbath-2283ef) , (https://www.the-ten-commandments.org/isthesabbathaceremoniallawormorallaw.html) , (http://www.sdanet.org/atissue/books/qod/q16.htm)) . What is the biblical basis for that claim? ________________________________ As requested in the comments, I'll briefly summarize the core ideas presented by some of these sites: 1. This [site](https://www.the-ten-commandments.org/isthesabbathaceremoniallawormorallaw.html) (and this follow-up [publication](https://www.the-ten-commandments.org/wasthesabbathabolished.html) on the same site) basically claims that the weekly sabbath belongs to the moral law, whereas the remaining feasts and holy convocations belong to the ceremonial law, and therefore they conclude that the weekly sabbath still stands but the others are abolished because they were "shadows". 2. This [site](http://www.sdanet.org/atissue/books/qod/q16.htm) essentially says the same thing: it talks about the concepts of "ceremonial law" and "moral law", claims that the weekly sabbath in particular is "moral" rather than "ceremonial", and, thus, concludes that the weekly sabbath is still in effect.