Someone should not say, "Allah and so-and-so"

Mughith claimed that Ibn 'Umar once asked him about his mawla and Mughith replied, "By Allah and so-and-so." Ibn 'Umar responded, "Do not speak like that. Do not put anyone with Allah. Say "so-and-so:
after you have said, "Allah."

حَدَّثَنَا مَطَرُ بْنُ الْفَضْلِ، قَالَ: حَدَّثَنَا حَجَّاجٌ، قَالَ ابْنُ جُرَيْجٍ: سَمِعْتُ مُغِيثًا يَزْعُمُ، أَنَّ ابْنَ عُمَرَ سَأَلَهُ: مَنْ مَوْلاَهُ؟ فَقَالَ: اللَّهُ وَفُلاَنٌ، قَالَ ابْنُ عُمَرَ: لاَ تَقُلْ كَذَلِكَ، لاَ تَجْعَلْ مَعَ اللهِ أَحَدًا، وَلَكِنْ قُلْ: فُلاَنٌ بَعْدَ اللهِ.