You Don't 'see' it in the above displayed before your eyes SCRIPTURE.
You Won't 'see' it because of your fear, because of your lack of knowledge, because of your cultivated distaste for the Sabbath of the Lord Jesus, because of your love for being esteemed among the deaf and blind.
You Will not 'see' it-- Will not, see this: The whole chapter, the greatest of Paul's sermons, with the Theme the battle-cry of his life. (One could say chapter 15 is Paul's only sermon he ever preached.) In the same way somehow or other the same chapter 15 recurs through all Paul's Letters. But what the Sundayers hate more than anything is to realise Paul preached this sermon before the Church of Christ Followers WEEKLY ON THE SABBATH DAY.
Following Paul's missionary journeys we find him preaching THIS sermon BEFORE THE CONGREGATION, just as regularly as he used it as theme and argument in all diatribe, dialogue, proclamation, confession, PRAYERS, <evangelising> or Letter or any other occasion of fellowship and worship -- i.e., ANY OCCASION OF GOING TO CHURCH – any occasion of <missionary outreach>.
Now do not even try the two solitary texts the Sunday-legalists have through all the centuries of heresy and idolatry in an apostate Christianity ABUSED without a blush of SHAME OR CONSCIENCE. By now the naked stupidity of the attempt has become a BORING INSULT TO INTELLIGENCE.
So where is the pulpit implied in the passage of Scripture <<that Paul .. on the sabbath day preached from>>? There, in the Church! The pulpit was the one Paul would have USED (even were it a tree-trunk next to a water stream) "on the Sabbath" the Day TO <preach> on, not <supposedly>, but the God-instituted "SABBATH TO HEAR THE WORD OF GOD ON".
If you are inferring Hebrews 4th chapter, then what about the words of Paul that says otherwise for what you are emphasizing for Gentiles to observe the sabbath day?
Romans 14:4 Who art thou that judgest another man's servant? to his own master he standeth or falleth. Yea, he shall be holden up: for God is able to make him stand. 5 One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind. 6 He that regardeth the day, regardeth it unto the Lord; and he that regardeth not the day, to the Lord he doth not regard it. He that eateth, eateth to the Lord, for he giveth God thanks; and he that eateth not, to the Lord he eateth not, and giveth God thanks. 7 For none of us liveth to himself, and no man dieth to himself. 8 For whether we live, we live unto the Lord; and whether we die, we die unto the Lord: whether we live therefore, or die, we are the Lord's.
That has to include the regular sabbath and not just the annual sabbath for why no believer can judge a believer that regard the sabbath day or when a believer does not regard that day.
Colossians 2:15 And having spoiled principalities and powers, he made a shew of them openly, triumphing over them in it. 16 Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days: 17 Which are a shadow of things to come; but the body is of Christ.
I have given you scripture for why what you say cannot be true.
Acts 20:7 And upon the first day of the week, when the disciples came together to break bread, Paul preached unto them, ready to depart on the morrow; and continued his speech until midnight.
1 Corinthians 16:1Now concerning the collection for the saints, as I have given order to the churches of Galatia, even so do ye. 2 Upon the first day of the week let every one of you lay by him in store, as God hath prospered him, that there be no gatherings when I come.
Sabbath ends Saturday at sunset and the first day of the week starts at sunset on Saturday.
Now while I have given scripture for when collection was held to take a portion from it of that collection for the support of the missionaries in the field AND the breaking of the bread is on the first day of the week, you do not have one scripture testifying of Paul preaching from the pulpit on the sabbath day.
The Good News is that if you did not regard the sabbath day perfectly, it doesn't matter because Jesus is in you and is with you always for why you are guiltless as it is His righteousness apart from the law that makes you stand.
Romans 3:26 To declare, I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus. 27 Where is boasting then? It is excluded. By what law? of works? Nay: but by the law of faith. 28 Therefore we conclude that a man is justified by faith without the deeds of the law.
So preach Jesus Christ and Him crucified. That is by Whom we are justified by; and not by the keeping of the sabbath day.