Meaning

Bismihi ta'ala

At the end of times, prior to Qiyamah, there will be Raj'ah; the return of the purest and the return of the wickedest. 

This is when retribution will happen, and those responsible for the worst of oppression will be held accountable for what they did. 

This means that in Heaven there will be no more sorrow or grief or sadness. Indeed, as our ahadith say, attending the Majalis of Imam Husain (a.s.), weeping for him and the tragedy of Karbala, writing poem for him, and everything related to serving Imam Husain (a.s.) will amount to mandatory entering of Heaven. 

This itself is the greatest blessing, if we do it sincerely and with correct ma'rifah, truly recognising the status of the Imam and following his teachings in practice.

If we are fortunate enough, we could also be in the vicinity of Imam Husain (a.s.) and Ahlul Bayt (a.s.) in Heaven, in shaa Allah.

And Allah knows best.

Bismihi ta'ala

This is a common expression we use as Muslims, and can be interpreted in different ways. 

Initially, ما شاءَ اللهُ is three words, ma (anything/what/whatever), shaa` (will/want/desire/request) and Allah.

When we utter this, we are expressing God's power and will over us.

It means anything that Almighty God wills happens, and whatever God wants will happen. When we say it, we are confirming that it is God's will and what He wants, and not our will, or what people want, even if they dont want it, or hate it, if it is the will of God, it will happen. 

It is highly recommended to say this dhikr, especially beginning the day by saying bismillah, ma shaa Allah. 

The custom is also that this statement is said to repel evil eye and envy. So, when you see something/someone nice, to repel evil eye and envy, you say ma shaa Allah. 

And Allah knows best.