What does « Four / Thursday » mean in the Quran?

And for you is half of what your wives leave if they have no child. But if they have a child, for you is one fourth of what they leave, after any bequest they [may have] made or debt. And for the wives is one fourth if you leave no child. But if you leave a child, then for them is an eighth of what you leave, after any bequest you [may have] made or debt. And if a man or woman leaves neither ascendants nor descendants but has a brother or a sister, then for each one of them is a sixth. But if they are more than two, they share a third, after any bequest which was made or debt, as long as there is no detriment [caused]. [This is] an ordinance from Allah, and Allah is Knowing and Forbearing.

Those who commit unlawful sexual intercourse of your women - bring against them four [witnesses] from among you. And if they testify, confine the guilty women to houses until death takes them or Allah ordains for them [another] way.

[Allah] said, "Then indeed, it is forbidden to them for forty years [in which] they will wander throughout the land. So do not grieve over the defiantly disobedient people."

And We made an appointment with Moses for thirty nights and perfected them by [the addition of] ten; so the term of his Lord was completed as forty nights. And Moses said to his brother Aaron, "Take my place among my people, do right [by them], and do not follow the way of the corrupters."

So travel freely, [O disbelievers], throughout the land [during] four months but know that you cannot cause failure to Allah and that Allah will disgrace the disbelievers.

Indeed, the number of months with Allah is twelve [lunar] months in the register of Allah [from] the day He created the heavens and the earth; of these, four are sacred. That is the correct religion, so do not wrong yourselves during them. And fight against the disbelievers collectively as they fight against you collectively. And know that Allah is with the righteous [who fear Him].

They will say there were three, the fourth of them being their dog; and they will say there were five, the sixth of them being their dog - guessing at the unseen; and they will say there were seven, and the eighth of them was their dog. Say, [O Muhammad], "My Lord is most knowing of their number. None knows them except a few. So do not argue about them except with an obvious argument and do not inquire about them among [the speculators] from anyone."

And those who accuse chaste women and then do not produce four witnesses - lash them with eighty lashes and do not accept from them testimony ever after. And those are the defiantly disobedient,

And those who accuse their wives [of adultery] and have no witnesses except themselves - then the witness of one of them [shall be] four testimonies [swearing] by Allah that indeed, he is of the truthful.

But it will prevent punishment from her if she gives four testimonies [swearing] by Allah that indeed, he is of the liars.

Why did they [who slandered] not produce for it four witnesses? And when they do not produce the witnesses, then it is they, in the sight of Allah, who are the liars.

Allah has created every [living] creature from water. And of them are those that move on their bellies, and of them are those that walk on two legs, and of them are those that walk on four. Allah creates what He wills. Indeed, Allah is over all things competent.

[All] praise is [due] to Allah, Creator of the heavens and the earth, [who] made the angels messengers having wings, two or three or four. He increases in creation what He wills. Indeed, Allah is over all things competent.

And He placed on the earth firmly set mountains over its surface, and He blessed it and determined therein its [creatures'] sustenance in four days without distinction - for [the information] of those who ask.

And We have enjoined upon man, to his parents, good treatment. His mother carried him with hardship and gave birth to him with hardship, and his gestation and weaning [period] is thirty months. [He grows] until, when he reaches maturity and reaches [the age of] forty years, he says, "My Lord, enable me to be grateful for Your favor which You have bestowed upon me and upon my parents and to work righteousness of which You will approve and make righteous for me my offspring. Indeed, I have repented to You, and indeed, I am of the Muslims."

Have you not considered that Allah knows what is in the heavens and what is on the earth? There is in no private conversation three but that He is the fourth of them, nor are there five but that He is the sixth of them - and no less than that and no more except that He is with them [in knowledge] wherever they are. Then He will inform them of what they did, on the Day of Resurrection. Indeed Allah is, of all things, Knowing.