Scriptures declare that God or Brahman is the cause of Bliss

I.1.14

तद्धेतुव्यपदेशाच्च |

taddhetuvyapadeshAchca

and because Brahman is declared to be the cause of it (i.e. Bliss or Ananda) it implies that the suffix 'maya' denotes abundance

Tad + Hetu(तद् + हेतु): The cause of that (i.e. bliss or ananda); vyapadeshAt(व्यपदेशात्):  because of statement of declaration; cha(च): and;

Commentary:

The scriptures declares that Brahman or God is the cause of the bliss.

"Esha hyevanandayati—For he alone causes bliss” Taittereya . Up.II-7.

He who causes bliss must himself abound in bliss, just as a man who enriches others must himself be in possession of abundant wealth. The giver of bliss to all is Bliss itself. Hence Anandamaya (abundance of bliss) is Brahman or God

Background

Introduction - part1, part2, part3, part4

Sutra - I.1.1, I.1.2, I.1.3, I.1.4, I.1.5, I.1.6, I.1.7, I.1.8, I.1.9, I.1.10, I.1.11, I.1.12, I.1.13

Anandamaya means not a derivative from Bliss BUT Abundance of Bliss

I.1.13

विकारश्ब्दान्नेति चेत् न प्राचुर्यात् | 

vikArashbdAnneti chet na prAchuryAt

Anandamaya does not mean a modication or transformation or product of bliss but rather refers to Abundance of bliss as denoted by the suffix maya

Vikarashbdat(विकारश्ब्दात्): From the word "Anandamaya" with the suffix "Mayat" denoting modification; Na(न): is not; iti(इति): this, thus; Chet(चेत्): if; Na(न): Not so; Prachuryat(प्राचुर्यात्): because of abundance;

Commentary:

The word maya cannot mean modification because we cannot predicate such a modification to Brahman(God) who is changeless. Here Maya means abundance. Hence the word Anandamaya denotes the Brahman/Highest Self. 

Anandamaya does not mean the absence of pain or sorrow. It is a positive attribute of Brahman and not a mere negation of pain. Anandamaya means he whose essential nature is bliss. For e.g. Sun, whose essential nature is light is called Jyotirmaya. 

Background

Introduction - part1, part2, part3, part4

Sutra - I.1.1, I.1.2, I.1.3, I.1.4, I.1.5, I.1.6, I.1.7, I.1.8, I.1.9, I.1.10, I.1.11, I.1.12

Bliss is Brahman (GOD)

Topic 6 (sutras 12 - 19) : Anandamayadhikaranam [Anandamaya: blissful; adhikaranam: section, topic, proposition]

I.1.12

आनन्दमयोऽभ्यासात् |

Anandamayo`bhyasat

Anandamaya (Bliss) means Brahman (God) on account of repetition.

Anandamaya(आनन्दमया): full of bliss; Abhyasat(अभ्यासात्): because of repetition.

Commentary:

In the scriptures there are several words which are apparently ambiguous. The author takes up these words one after the other and shows it really applies to Brahman(God). In this sutra (theorem) he picks up the word Anandamaya

Taittiriya upanishad says:

Raso vai sah. Rasam hyevayam labdhvanandi bhavati - He the Highest Self is Bliss in itself [II-7]

Anandam Brahmeti vyajanat - Bliss is Brahman [III-6]

This sutra(theorem) establishes that Anandamaya(bliss) is Brahman(God)

Background

Introduction - part1, part2, part3, part4

Sutra - I.1.1, I.1.2, I.1.3, I.1.4, I.1.5, I.1.6, I.1.7, I.1.8, I.1.9, I.1.10, I.1.11