Dought & clear, - Is this expression correct?.

Is there anything wrong with this expression: "If we knew what was
going to happen in the future we could have saved ourselves a lot of
trouble"?.
Praise be to Allaah.
What this expression means if that if a person knew what was going to
happen to him, which is a matter of the unseen, he would have been
able to avoid the problems and evil that have befallen him. This is in
accordance with the Muslim's belief ('aqeedah), and there is nothing
wrong with it, because the unknown is something that is known only to
Allaah. If it were the case that people could see the unseen and know
of events before they happen, they would have achieved everything good
and avoided everything bad. They would look at the causes of good
health, wealth and happiness and they would pursue them, and they
would look at the causes of poverty, disease and death and they would
avoid them. But this is something hypothetical and impossible. The
point is that man is incapable and weak and must submit to the fate
that Allaah, may He be glorified and exalted, has decreed for him.
Allaah says (interpretation of the meaning):
"Say (O Muhammadصلى الله عليه وسلم(: 'I possess no power over benefit
or hurt to myself except as Allaah wills. If I had the knowledge of
the Ghayb )Unseen(, I should have secured for myself an abundance of
wealth, and no evil should have touched me. I am but a warner, and a
bringer of glad tidings unto people who believe'"
[al-A'raaf 7:188]
It says inTafseer al-Qur'aan il-'Azeem(3/524):
The best comment concerning this is what was narrated by al-Dahhaak
from Ibn 'Abbaas: "If I had knowledge of the unseen I would have
acquired a lot of good" i.e., wealth. According to another report: "If
I knew the unseen I would have known what would make a profit and what
would not, and I would have made a lot of money and poverty would not
have come my way."
Ibn Jareer said: Others said: What that means is: If I had knowledge
of the unseen I would have prepared for the year of drought (by
setting side something) from the year of plenty, and I would have
known when prices were about to go up or down, so I would have saved
for myself from the times when prices were low for the times when
prices were high.
'Abd al-Rahmaan ibn Zayd ibn Aslam said: "and no evil should have
touched me" I would have avoided evil before it happened. End quote.
Shaykh al-Sa'di said inTafseer al-Kareem al-Rahmaan(p. 311): "If I had
the knowledge of the Ghayb (Unseen), I should have secured for myself
an abundance of wealth, and no evil should have touched me" means: I
would have done the things that I know would have resulted in good and
benefits for me, and I would have avoided everything that could lead
to evil and negative consequences, because I would have known about
things before they happened, and I would have known what they would
lead to.
But – because of my lack of such knowledge – bad things may happen to
me, and I may miss out on good things. This is the clearest evidence
that I have no knowledge of the unseen.
And Allaah knows best.