I have read and heard in the past : to the Eyes of Allah swt fasting is even greater than praying because a female that is in her period does not need to repay her Salaah but has to repay her fast. Was this a hadith an incident? I cant remember more details about this

This is not correct.
It was a discussion between Imam Sadiq ?A.S. and Abu Hanifa.
Imam Sadiq asked Abu Haeefa: Praying the greater or fasting?
Abu Haneefa said: prayer.
Imam said: Then why menstruating woman is asked to fast, and not asked to pray, after menses?
However, This does not mean that there is such comparison between the two.

I have read and heard in the past : to the Eyes of Allah swt fasting is even greater than praying because a female that is in her period does not need to repay her Salaah but has to repay her fast. Was this a hadith an incident? I cant remember more details about this

Thanks for clarifying the source and details

Namaz is the only ebadat in Islam which connects us to Allah swt everyday five times. This speciality of namaz makes this worship very important and necessary for every Abd ( salve of Allah). But Fasting is one of the unique act of worship of Allah swt because in any worship either namaz or hajj of zakat etc person doesn’t face any physical trouble and all these ebadaat are being done in public so riya can be easily included to them but fasting even if a person eats and drink silently no one can be aware about that and a person can pretend that he/ she is fasting but for sake of Allah he doesn’t do that so sincerity of Niyat maintains well.That’s why Allah swt has said I my self will be the reward of Fasting. What does it mean that no one can imagine or compare the reward of Fasting what Allah swt has selected for His believer.

I have read and heard in the past : to the Eyes of Allah swt fasting is even greater than praying because a female that is in her period does not need to repay her Salaah but has to repay her fast. Was this a hadith or an incident ? I cant remember more details about this

No this is not the case. One is not able to derive this based on the ruling, as this would be conjecture (qiyas) which is not permissible. Both prayers and fasting are obligatory and beloved to Allah (swt)