The scholar  Abdur Rahmaan ibn Nasir as Sa’dee rahimahullaah said about the statement of Allaah, the Most High:

<<No fruit emerges from its covering nor does any female become pregnant nor give birth to offspring except by His knowledge.
And on the Day when He will call them, “Where are My partners?” they will say, “We inform you that none of us bears witness.”>>
(Soorah al Fussilat (41) aayah 47

So no fruit emerges from any tree except that He is has detailed knowledge of it.

…nor does any female become pregnant – from the children of Adam, or other than them from the different types of animals, except with His knowledge.

nor give birth to offspring except by His knowledge – so how can the people of shirk equate with Him, He the Most High,  that which has no knowledge nor hearing nor seeing?

And on the Day when He will call them – meaning those people who make shirk with Him, on the Day of Resurrection, rebuking (them) and making manifest their lie. So He will say to them:

Where are My Partners? – those whom you claimed were My partners, such that you worshipped them, and argued over that, and showed enmity to the Messengers on account of them?

they will say – affirming the falsity of taking them (the false deities) as objects of worship and partners along with Allaah

We inform you that none of us bears witness – meaning we inform you, O our Lord, and bear witness upon us, that not one of us testifies that taking them as objects of worship and partners was something correct. So now all of us go back to (believing in the) falsity of worshipping them, and we declare ourselves free of them.

(Tafseer ul Kareem ir Rahmaan  of as Sa’dee rahimahullaah, translated by Nasser ibn Najam)

With regards to the reason why the reason why yawm ul qiyaamah (the Day of Standing) is so called,  Shaykh Muhammad ibn Saalih al ‘Uthaymeen rahimahullaah states:

And it is called yawm ul qiyaamah for three reasons:

1) The qiyaam (standing) of the people from their graves, as per His statement, He the Most High:

The Day when the people will stand before the Lord of all the Creation.
Soorah al Mutaffifeen (83)

2) The qiyaam (standing) of the witnesses, as per His statement, He the Most High:

We will indeed make Our Messengers victorious and those who truly believed in the life of this world; and the Day when the witnesses will stand forth.
Soorah Ghaafir (40) aayah 51

3) The qiyaam (establishment) of justice, as per His statement, He the Most High:
 
And We shall set up Balances of Justice on the Day of qiyaamah.
Soorah al Anbiyaa (21) aayah 47

(Al qawl ul mufeed (2/118) of Shaykh Muhammad ibn Saalih al ‘Uthaymeen rahimahullaah, translated by Nasser ibn Najam)