It is narrated, most likely as marfu’, from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that when he would raise his head from ruku’, after saying «سَمِعَ اللّٰهُ لِمَنْ حَمِدَهُ», he would say: «اَللّٰهُمَّ رَبَّنَا لَكَ الْحَمْدُ مِلْءَ السَّمَاءِ وَمِلْءَ الْأَرْضِ وَمِلْءَ مَا شِئْتَ مِنْ شَيْءٍ بَعْدُ» “O Allah! O our Lord! All praise is for You, which fills the heavens and fills the earth and fills whatever else You will.”