The provided tafsir sources do not explicitly define "heavens" (السَّمَٰوَاتِ) as "space" in the modern scientific sense. Instead, they describe "heavens" in a broader, more traditional cosmological context.

Linguistically, السَّمَٰوَاتِ is the plural form of سَمَاء (sama'), often translated as sky or heaven. Its usage in the Quran refers to the celestial realm.

Tafsir Ibn Kathir consistently uses "heavens" to encompass:

1. **Celestial bodies and phenomena:** "luminous stars, the firmaments, the moving planetary bodies, the sun and the moon," and "night and day, their alternating" (Source 3, 4). This includes elements visible in what we now call space, but also atmospheric phenomena.

2. **The source of divine activity:** Allah sends rain "from the heavens" (Source 3).

3. **A realm of Allah's knowledge and authority:** Allah's knowledge extends to "the heavens and on the earth" (Source 1, 6), and He created them (Source 5).

The Quranic context, particularly in verses like 10:101 and 10:5, highlights the "heavens and the earth" (السَّمَٰوَاتِ وَالْأَرْضِ) as distinct but interconnected realms containing signs of Allah's greatness and power. While encompassing celestial objects, the term's meaning is broader than merely empty space, referring to the entire upper creation.

📚 Sources: Classical tafsir (multi-source)