This is because, as seen from any one place on the Moon's surface, Earth remains in approximately the same position in the lunar sky, either above or below the horizon.
ðɪs ɪz bɪkˈʌz, æz sˈiːn fɹʌm ˌɛni wˈʌn plˈeɪs ɔnðə mˈuːnz sˈɜːfɪs, ˈɜːθ ɹᵻmˈeɪnz ɪn ɐpɹˈɑːksɪmətli ðə sˈeɪm pəzˈɪʃən ɪnðə lˈuːnɚ skˈaɪ, ˈiːðɚɹ əbˌʌv ɔːɹ bᵻlˌoʊ ðə hɚɹˈaɪzən.