Invocation to be recited while standing at Safa and Marwah
 

إِنَّ الصَّفَا والمَرْوَةَ مِنْ شَعائرِ الله…

'Innas-Safaa wal-Marwata min sha'aa'irillaah.  

Surely Safa and Marwah are among the signs of Allah. 

أَبْدَأُ بِمَا بَدَأَ اللهُ  بِهِ

'Abda'u bimaa bada'allaahu bihi.

I begin by that which Allah began.

He began (his Sa'y) at Mount Safa climbing it until he could see the House. He then faced the Qiblah repeating the words:

اللهُ أكْبَرُ ,  اللهُ أكْبَرُ , اللهُ أكْبَرُ .

Laa 'ilaaha 'illallaah, Allaahu 'Akbar

There is none worthy of worship but Allah, and Allah is the Most Great.

Then he said:

لا إِلهَ إلاَّ  اللهُ وَحْدَهُ  لا شَرِيكَ لَهُ، لَهُ المُلْكُ وَلَهُ الحَمْدُ وهُوَ عَلى كُلِّ شَيءٍ قَديرٌ، لا إِلَهَ إلا اللهُ وَحْدَهُ أَنْجَزَ وَعْدَهُ، وَنَصَرَ عَبْدَهُ وَهَزَمَ الأَحْزَابَ وَحْدَهُ

Laa 'ilaaha 'illallaahu wahdahu laa shareeka lahu, lahul-mulku wa lahul-hamdu wa Huwa 'alaa kulli shay'in Qadeer, laa 'ilaaha 'illallaahu ilahaahu, 'anjaza wa'dahu, wa nasara 'abdahu, wa hazamal 'ahzaaba wahdahu.

None has the right to be worshipped but Allah alone, Who has no partner, His is the dominion and His is the praise, and He is Able to do all things . None has the right to be worshipped but Allah alone, He fulfilled His Promise, He aided His slave, and He alone defeated Confederates.

Then he would ask Allah for what he liked, repeating the same thing like this three times . He did at Mount Marwah as he did at Mount Safa.

Reference: Muslim 2/888.