(through the land and seen what happened in the end to those before them Allah destroyed them completely,) which means that Allah punished them because of their denial and disbelief, and saved the believers from among them. That is why He says,
وَلِلْكَـفِرِينَ أَمْثَـلُهَا
(and a similar (end awaits) the disbelievers.) Then Allah says,
وَأَنَّ الْكَافِرِينَ لَا مَوْلَىٰ لَهُمْ (As for the disbelievers, there is no supporter them. - 47:11). The word for "mawla" is used in several different senses. One of its meanings is "protector" or "supporter". This is the sense in which it is used here. Another sense of the word is "owner/master". In Qur'an [ 10:30] we come across: وَرُدُّوا إِلَى اللَّـهِ مَوْلَاهُمُ الْحَقِّ "They will be returned to Allah, their Master, the Truth" (10:30). In this phrase, Allah is called the "mawla" of the infidels, that is, their Master / Owner because the mastership / ownership of Allah extends over all - the believers as well as the non-believers; without any exclusion.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 11–12
The One who causes events to occur is God. But He does so through the chain of cause and effect. Such is the case with religion also. It is God’s desire that the force of falsehood should be destroyed and Truth should eternally prevail throughout the world. But in order that this should happen, Almighty God requires certain individuals to serve as the human medium for this Divine Action. This process is termed here as ‘assisting God’. When a group rises to assist God it simultaneously performs another task, i.e. it proves unbelievers to be such. The individuals assisting God with extreme seriousness and sincere well-wishing call the people towards God. Distancing themselves from such behaviour as is opposed to the Truth, they bear testimony to the truth of religion (din). They establish the Truth as such to the ultimate degree. In this way, the process of the conclusion of argument in missionary work is completed; this is required by Almighty God for His judgement in the Hereafter. The upholders of truth become dominant over the upholders of untruth, provided the former do dawah work which is a prerequisite for seeking divine support.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.