John 9:4-5 why these two verses inserted into the context?

John 9:1-3 6-7 they are coherent. Why there are 4-5 verses?

I think Jesus talked from the context because in verse 3 “Neither this man nor his parents sinned,” said Jesus, “but this happened so that the works of God might be displayed in him.
he mentions here the work of God…so he talks about the work which must Father gave and sent accomplish on this earth …

so he says verse 4
I must work the works of him that sent me
This shows, that the works of God, that were to be manifest, were to be done by Christ: many were the works which the Father gave him to do, and which he undertook to perform; and therefore there was a necessity of doing them, as principally the work of redemption, by fulfilling the law, and satisfying justice: and besides this, there were the preaching of the Gospel, and doing of miracles, and among these was this of giving sight to the blind, see ( Isaiah 35:5 ) , both in a natural and spiritual sense: and with a view to this he speaks of the works he mast do,

while it is day;
while the day of life lasts, for in the grave there is no work nor device:

the night cometh when no man can work;
meaning the night of death, and of the grave, and suggesting his own death hereby, that he had but a little time to be in this world, and therefore would make the best use of it, to do the will and work of his Father that sent him; and which should be a pattern to us. This life is but short, it is but as the length of a day; a great deal of business is to be done; and death is hastening on, which will put a period to all working.
(5) As long as I am in the world, I am the light of the world.—Better, when I am in the world. The thought is that the two things necessarily co-exist. He is the true Light, and this true Light cannot be in the world without shining in its darkness. (Comp. Note on John 1:5.) The thought is here closely connected with His teaching in the Temple but a short time before (John 8:12, “I am the Light of the world”), and also with the removal of physical and spiritual darkness which immediately followed.

Because he is talking about the work of God so he is warning his disciples to do the work of God according to the time because if we lose the time then we may not have the opportunity to fulfills it

I think its not inserted its an continual story

The Father, who sent Christ into the world, gave him work to do: his general work was, to glorify God upon the earth, John 17:4, as by working out the redemption of man, so by revealing his will to the sons of men, and working miracles for the glorifying the name of God. Saith Christ, I have a set time to work in; that is, that which he here calleth day, the time wherein Christ was to live upon the earth.

The night cometh, when no man can work; I am not to be here always, there will come a time when I must be absent from the earth, then none of this work can be done. A good argument to persuade every Christian to work while the time of his life lasts, for the night of death will come, when no man can any longer work out his salvation; but as the tree falleth, so it must lie, Ecclesiastes 9:10.

Jesus was explaining his life and what he was doing.