Abu Sufyan and a number of leaders from Quraysh needed something from the Khalifa, Umar ibn al-Khattab, so they approached his house and knocked on his door. Simultaneously, Bilal, Suhayb, and some poor Muslims were there for their own need. Umar's assistant opened the door and..

admitted Bilal and Suhayb's group and did not so much as glance at the leaders of Quraysh.
Abu Sufyan became livid: "I've never ever seen anything like this! He admits these former slaves and doesn't even look at the leaders!?"

Suhayl was the wisest of them and he said, "If you're angry at this, you ought to only be angry at yourselves. There was a time when you were called and they were called. They answered the call, and you refused it. (The call to Islam).

What you missed out of virtue from answering that first call should anger you far more than not being let into a door before somebody else. If this upsets you, how you will be on the Judgement Day when they are called first to Paradise, and you are left sitting, ignored."

Hasan al-Basri commented, "Those who answer Allah's call will never be treated like those who didn't."

--Imam Ahmad, Book of Zuhd

Umar's action is supported in the Quran: "They are not equal those who sacrificed and fought before the Opening" (57:10 Hadeed).

"They are not equal those who sacrificed and fought before the Opening. Those ones are greater in virtue that those who sacrificed and fought afterwards. And all are promised good" (57:10 Hadeed).

‌ؕ لَا يَسۡتَوِىۡ مِنۡكُمۡ مَّنۡ اَنۡفَقَ مِنۡ قَبۡلِ الۡفَتۡحِ وَقَاتَلَ‌ؕ اُولٰٓٮِٕكَ اَعۡظَمُ دَرَجَةً مِّنَ الَّذِيۡنَ اَنۡفَقُوۡا مِنۡۢ بَعۡدُ وَقَاتَلُوۡا‌ؕ وَكُلاًّ وَّعَدَ اللّٰهُ الۡحُسۡنٰى‌ؕ